Acoustic signals generated by turbulent blood flow may be utilized for the non-invasive detection of stenosis. To detect acoustic signals generated by turbulent blood flow, an array of sensors are placed on a patient's chest. Typically, these sensors have been configured in a fixed array such that the spatial relationship between the sensors was known. However, because patients differ in physical characteristics, it may be advantageous to use discrete sensors which may be positioned on a patient in an optimal "acoustic window" for monitoring blood flow.
One problem which may arise in a system where discrete sensors are utilized to detect acoustic signals relates to the determination of the spatial relationship of the sensors. In order to utilize advanced beam forming techniques on the received signals at the sensors, it is preferred that the spatial relationship of the sensors be accurately determined. One technique which may be utilized to determine the locations of the sensors involves an articulating arm which is calibrated and used to make physical measurements of the sensor locations by placing the tip of the articulating arm at each of the sensor locations. However, the use of an articulating arm may be slow and the contact between the arm and the patient or the sensor may move the sensor and unfortunately, thereby, provide an inaccurate reading. Furthermore, if the locations of the sensors are dynamically determined, by whatever technique, such a determination may still not provide a sufficiently accurate spatial relationship of the sensors as it is the point of contact between the sensors and the patient which are utilized in beam forming. These contact points are obscured once the sensors are placed on the patient and, therefore, may be difficult, if not impossible, to directly measure.
In light of the above discussion, a need exists for improvements in the determination of the spatial relationship between sensors placed on a patient.